Fluid filter with removable central component with additional retainer

ABSTRACT

The invention relates to a fluid filter, especially an oil filter for an internal combustion engine, comprising a filter housing and a central, approximately tubular component which extends into the interior of the filter, said central component engaging in the operating position a projection located on the filter housing and permanently retained in the filter housing, said component being disengageable from said projection and nondestructively removable in said disassembly position from the filter, the component being rotatably mounted around its longitudinal axis within the filter housing, a retaining component ( 10 ) being arranged in rotatably restricted fashion within the filter housing, which retaining component in its operating position surrounds and fixes the central component by means of a clamping or locking interference fit, and the central component being rotatable in its disassembly position when the clamping or locking force is exceeded.

FLUID FILTER WITH REMOVABLE CENTRAL COMPONENT WITH ADDITIONAL RETAINER

[0001] The invention relates to a filter according to the preamble ofclaim 1.

[0002] Utility model application 299 16 265 describes such a filter.

[0003] The central component here is provided with lateral wings whichcontact projections in the interior of the filter housing and in thisway rotationally fix the central component. In response to bending orintentional destruction of these wings, the central component may bepivoted into a rotated position around its rotational axis, in whichposition it is removable.

[0004] The object of the present invention is to further develop ageneric fluid filter such that this filter allows for easy assembly anddisassembly of the central component, even given greatly varying filtergeometries and correspondingly varied installed conditions within thefilter housing.

[0005] This fundamental object of the invention is achieved by a fluidfilter having the characteristics of claim 1 or claim 3.

[0006] The invention, in other words, proposes two different approaches:On the one hand, it is possible to arrange the central component to berotationally fixed. For this purpose, the central component issurrounded by a retaining component which in turn is arranged in arotationally fixed manner within the filter housing. Specifically, inconnection with irregularly contoured filter housings, the retainingcomponent may be designed such that it may be mounted only axially inthe filter housing and is not rotatable—even rotatable by a few angulardegrees. On the other hand, the central component is essentially free torotate within the filter housing. However, due to the matchingcontouring between retaining component and central component, thecentral component is fixed so as not to rotate, or to rotate only to alimited extent, within the filter housing. The central component isaxially secured here in the familiar fashion, e.g., by spring-elastic,outwardly projecting engagement hooks which engage the matchingprojections in the filter housing. Since the projections, as well as theengagement hooks, do not extend around the entire circumference of thefilter housing or central component, the central component may berotated by partially turning it around its longitudinal axis from itsoperating position to the disassembly position in which its engagementhooks may be axially displaced between two adjacent projections of thefilter housing such that the central component may be removed from thefilter housing in this disassembly position. The retaining componentassembly itself does not need to be additionally fixed within the filterhousing: It is movable only in an axial direction, and both componentsare axially fixed in the axial direction due to the connection with thecentral component and the axial fixation of the latter, e.g., by meansof the above-mentioned spring-elastic claws. The rotational fixation isin turn achieved by appropriate contouring between the central componentand the retaining component and the rotationally restricted mounting ofthe retaining component within the filter housing.

[0007] The forces needed to rotate the central component relative to theretaining component from its operating position into the disassemblyposition are set so high that lesser rotational forces, such as thosewhich occur when the cap of the filter housing is screwed on orunscrewed and which are at least partially transferred to the centralcomponent, cannot result in any rotation of the central componentrelative to the retaining component. If required, it is even possible toprovide special keyed surfaces or similar features on the centralcomponent such that rotation of the central component relative to theretaining component may be enabled only with the aid of a tool.

[0008] An alternative approach of the invention is not to have thecentral component engage a projection which is provided directly on thefilter housing. This approach allows the filter housing to be fabricatedinexpensively without the requirement of an undercut. The projectionengaging the central component may instead by achieved by an additionalretaining component, this retaining component being detachably connectedto the filter housing, specifically being advantageously screwed on incombination with the filter housing.

[0009] Both of the proposals of the invention for the retainingcomponent may entail a combination component which in addition to havinga purely retaining function may also have additional functions andsupport appropriate functional components or functional assemblies. Forexample, preassembled valve assemblies may be included in thecombination assembly, which valve assemblies have, e.g., permanentlyintegrated valve bodies, while the sealing faces or valve seats matchingthese valves may be provided in the filter housing such that the valveis assembled in the filter housing along with the insertion of thecombination component.

[0010] The following discussion explains two embodiments of theinvention based on the drawings.

[0011]FIG. 1 shows a vertical section through a first embodiment.

[0012]FIG. 2 shows a cross-section of the filter in FIG. 1.

[0013]FIG. 3 shows a vertical section through a second embodimentcorresponding to lines A-A in FIG. 4.

[0014]FIG. 4 shows a cross-section of the embodiment of FIG. 3corresponding to the line B-B in FIG. 3.

[0015]FIG. 5 shows a cross-section of the embodiment of FIG. 3 alongline C-C of FIG. 3.

[0016] Filter 1 in FIG. 1 is a filter having a filter housing 2 and acap 3 screwed on to filter housing 2, with a replaceable filter insert 4being provided, including the actual filter medium, for example in theform of a folded filter surface, being provided within filter 1.

[0017] Filter housing 2 is designed to be not rotationally symmetricalover its entire length, for example, due to the design restrictions ofthe crankcase. With certain installed components such as a valveassembly 5, for example filter 1 is thus not freely rotatable around itslongitudinal axis within filter housing 2. A central component 6 isprovided within filter insert 4. This component is essentially tubularin form but includes recesses which allow filtered oil to flow downwardwithin filter insert 4 to the lubricating points of the internalcombustion engine. Central component 6 is designated as a support domesince it prevents the filter material from collapsing under the pressureand temperature conditions occurring during operation. As a result,filter insert 4 is of an inexpensive design which does not require anyrigid internal support device for the filter medium.

[0018] At its lower end, central component 6 has multiple retainingclaws 7 each of which engages a projection 8 in filter housing 2.Projections 8 are not designed as one circumferential, annularprojection but as individual projections between which spaces areprovided. When central component 6 rotates around its lengthwise axisrelative to its operating position as shown, retaining claws 7 areallowed to pass through these spaces between projections 8 such that inthis rotated position or disassembly position, central component 6 maybe removed from filter housing 2. Since central component 6 has acircumferential lower collar 9, valve assembly 5 is held in the positionshown by central component 6. Valve assembly 5 here is part ofcombination component 10 which includes multiple functional elements onbase plate 11, e.g., an additional valve assembly 5, as shown in FIG. 2,which is similar or identical in design to the valve assembly shown inFIG. 1. On its base plate 11, combination component 10 additionally hasfitting 12 with a roughly C-shaped cross-section. This fitting 12surrounds central component 6 - both the outer contour of centralcomponent 6 and the inner contour of fitting 12 being of polygonaldesign such that an anti-rotational clamping or locking is achieved inwhich central component 6 is retained within fitting 12, and thus withincombination component 10, such that this combination component 10 isalso designated as a retaining component.

[0019] When the clamping force between fitting 12 and central component6 is exceeded, the central component may be rotated and assume itsdisassembly position in which it may be removed from filter housing 2with retaining claws 7 through the spaces between projections 8. Aftercentral component 6 is removed along with its lower collar 9 from filterhousing 2, retaining component 10 may also be removed such that, e.g.,valve assemblies 5 may be replaced.

[0020] The polygonal design of fitting 12 and central component 6advantageously ensures that after rotation of central component 6 intoit disassembly position, this central component 6 automatically retainsthis rotational position - with the result that manipulation isfacilitated, and the user does not need to maintain central component 6in its rotational orientation of disassembly since this position ismaintained automatically.

[0021]FIG. 3 shows a second embodiment of the innovation in whichcentral component 6 has no retaining claws—with the result that filterhousing 2 is not provided with any undercuts, and fabrication of filterhousing 2 is accordingly less expensive and simpler than in theembodiment of FIG. 1. In this case, the projection engaging centralcomponent 6 is formed by retaining component 10: This retainingcomponent 10 also has a fitting 12, and as FIGS. 4 and 5 show, this doesnot exhibit a polygonal contour. It extends downward over collar 14 oncentral component 6 such that here too central component 6 engages aprojection which is fixed in place on filter housing 2, this projectionbeing, however, formed by fitting 12 of retaining component 10, and thisretaining component 10 includes a base plate 11 which supports valveassemblies 5 and screws 15 by which retaining component 10 is fastenedby screws to filter housing 2. Due to this screw attachment, theprojection formed by fitting 12 which engages central component 6 issimilarly a filter-fixed or housing-integrated projection.

[0022] Base plate 11 of retaining component 10 has two depressions 16which can accommodate the screw heads of screws 15. This design ensuresthe vertical mobility of retaining component 10 relative to filterhousing 2, the screw head forming a stop for depression 16 such thatretaining component 10 is permanently attached to filter housing 2.

[0023] If valve assembly 5 is intended, for example, to act as a drainvalve, as shown in FIG. 3, spring 17 can lift base plate 11 and thusentire retaining component 10 after cap 3 is unscrewed such that theplate-like valve body of valve assembly 5 is lifted from its valve seatand any residual oil located within filter housing 2 can be drained—withthe result that subsequent removal of filter insert 4 may beaccomplished with as few drops forming and as cleanly as possible.

1. Fluid filter, especially an oil filter for an internal combustionengine, comprising a filter housing and a central, approximately tubularcomponent which extends into the interior of the filter, said centralcomponent in the operating position engaging a projection on the filterhousing and being permanently retained in the filter housing, saidcomponent being detachable from said projection, and in this disassemblyposition being nondestructively removable from the filter, characterizedin that the component (6) is mounted rotatably around its longitudinalaxis in the filter housing (2), a retaining component (10) beingarranged in a rotationally restricted manner within the filter housing(2), which retaining component surrounds and fixes the central component(6) by clamp or locking interference fit so as not to rotate in itsoperating position, the central component 6 being rotatable into itsdisassembly position when the clamping or locking force is exceeded. 2.Filter according to claim 1, characterized in that the central component(6) and the retaining component (10) have interacting polygonalcontours.
 3. Fluid filter, especially an oil filter for an internalcombustion engine, comprising a filter housing and a central,approximately tubular component which extends into the interior of thefilter, said central component in the operating position engaging aprojection located in the filter housing and being permanently retainedin the filter housing, said component being disengageable from saidprojection and nondestructively removable in this disassembly positionfrom the filter, characterized in that the central component (6) isretained in a positive manner by a retaining component (10) which isscrewable onto the filter housing (2), the retaining component (10)forming the projection.
 4. Fluid filter according to one of claims 1 to3, characterized in that the retaining component (10) is designed as acombination component which includes a support body such as a base plate(11), multiple functional elements being located on the support bodysuch as valve assemblies (5) with valve bodies, or a clip fixing thecentral component (6), or a projection or screw holes fixing the centralcomponent (6).
 5. Fluid filter according to claim 4, characterized inthat each screw hole is located in a depression (16) accommodating thescrew head.